1. Field of the Invention
The present patent application refers to a special equipment used to cut and model sheets of leather or other modellable materials, in order to produce semi-finished products with desired profile and shape, designed to be incorporated in a more complex product obtained from moulding.
2. Description of Related Art
In particular, the process and equipment of the invention have been devised to solve a problem that is frequently encountered in the footwear sector, which refers to the fabrication of moulded outer soles and bottoms with built-in decorative inserts or constructive components made of natural or synthetic leather or other modellable materials.
According to the technique that is currently used to produce the said bottoms, leather inserts are cut out from a leather sheet, using special socket punches/cutters that cut a flat piece with predefined dimensions and profile and punch holes or slots in the piece, as well as seams or decorative cuts on the piece surface.
These semi-finished products are then loaded in the mould used to obtain the bottom, in such a way that the insert can be applied and fixed to the bottom during moulding, applying adhesive substances on the insert surface to guarantee strong uniform adherence between moulding material and insert.
This technique, which has been used for a long time, is advantageous in case of inserts with flat profile loaded in the mould in horizontal position, such as against the bottom wall of the mould impression.
However, problems arise when inserts are given a three-dimensional shape before being loaded in the mould, such as for example a cup shape with profile perfectly matching the profile of the walls where inserts are to be positioned.
In this case, after punching, the flat leather piece is modelled by special moulds.
In spite of the techniques used during modeling to guarantee stability of shape, no rapid, inexpensive and safe process has been devised so far to prevent the flat punched piece from springing out of shape.